Accept i64 seeds to better replicate the java.util.Random API

[dbdr]

java.util.Random acceps seeds of Java type long, which are signed 64 bits ints, i.e. i64 in Rust. Since the purpose of this crate is to replicate java.util.Random, wouldn't it make more sense to accept i64 seeds instead of u64?

[coderbot16]

Didn't realize that I had notifications disabled on this repository! It appears that i64 is used internally, and Random::new immediately casts the u64 to i64. It probably wouldn't be too difficult to change, I'll test changing Random::new to just take an i64 locally with my code that uses it and make sure it doesn't break anything.

[dbdr]

Did you get the chance to try it?